Laser Printers


The two charges inside of the laser printer are either the drum which is given a positive charge by a charge carona wire or a laser rod which are both negatively charged and provide the same outcome.


Laser Printers use ink and to get the ink from the ink container to the paper it has to use electrostatics. Inside the printer the two things that use electrostatics are the drum which has a positive charge inside of it and the very small laser rod that has a negative charge. They work together to produce a invisible electrostatic format on the paper, the ink used is kept positively charged so when the drum is rolled through the ink and the ink sticks to the parts that are currently negatively charged by the negatively charged laser rod causing an image to form on the drum. When the paper is fed through the printer it is given a temporary negative charge so the positive ink on the drum is attracted to the paper. So the ink will stay and dry on the paper it is heated so that it will be absorbed by the fibres in the paper and it becomes a permanent image. Colour printing applies the same process but it is done over several times because the coloured ink has to be applied to the paper one colour at a time.

Types of Negative Charges

- Small laser rod

- Charge corona wire

The drum is originally positive, it is given a positive charge by a special wire called a charge corona wire which has an overall negative charge from an electric current that runs through it. Not all laser printers use the wire some use charged roller instead but the outcome and process is the same.

Printers are used by offices, businesses, homes, and many more.

Operation Principle of Laser Printer